1. Field of the Invention
This invention relates to a multi-cabinet assembly and more particularly to an interlocking system for locking and unlocking slave doors of slave cabinets arranged adjacent to a master cabinet.
2. Description of the Related Art
Multi-cabinet assemblies comprise a number of single cabinets which are arranged next to one another to form a serial arrangement of cabinets. One of the cabinets which is normally arranged at one end of the multi-cabinet assembly is a so-called master cabinet with a corresponding master door whereby the other cabinets are so-called slave cabinets with corresponding slave doors. Such an arrangement of master and slave cabinets is for example used for housing electric and electronic equipment for controlling a stock of engines, a production line, etc.
To prevent an opening of the slave doors without switching-off a power supply for the electric and electronic equipment inside the cabinets an interlocking system is provided. By this interlocking system opening of the slave doors is only possible in case the master door of the master cabinet is opened. The interlocking system comprises one or more interconnecting rods which are usually slidably supported at an upper door frame of the cabinets. One of the interconnecting rods is movably connected to the master door. When the master door is opened it pushes a first interconnecting rod whereby this movement is transferred to all the other interconnecting rods connected with one another and with the first interconnecting rod.
Instead of a plurality of interconnecting rods it is also possible to use only one interconnecting rod movably connected at one end to the master door and extending along all slave cabinets.
The interlock system further comprises a locking means and a counterlocking means whereby the locking means is arranged at and movable with the interconnecting rod and the counterlocking means is arranged at each slave door. When all doors are closed the interconnecting rod is in such a position that the locking means are in an engagement position in which locking means and counterlocking means are in engagement for locking the slave doors. By opening the master door the interconnecting rod or interconnecting rods are pushed to place the locking means in a release position in which the locking means and the counterlocking means can be separated and the slave doors can be opened by corresponding door handles.
After the master door is closed and all the locking means are back in engagement position the locking means and counterlocking means can again enter engagement by closing the slave doors.
A known multi-cabinet assembly uses a counterlocking means essentially extending in horizontal direction and parallel to the interconnecting rod. The counterlocking means has an L-shaped cross-section whereby one vertical L-shank is used for fixing the locking means at the slave door and whereby the horizontal L-shank has an upward tilted end portion for engagement with the locking means. This locking means is formed like a hook that is pivotable about a horizontal axis. This axis is fixed by a bracket to the interconnecting rod. The interconnecting rod is guided through that bracket and has a ramp-like engagement portion for lifting the hook in release position.
After the interconnecting rod is pushed back to engagement position the hook is pivoted upwards by the end portion of the horizontal L-shank when the slave door is closed and because of gravity the hook comes again in engagement with the locking means after the slave door is closed to lock this door.
The known multi-cabinet assembly sometimes provides the problem that the slave doors which are hinged on one side arc, due to a wrong leveling of the cabinets on an unleveled floor, a little bit distorted or lopsided so that a proper engagement of the locking means and counterlocking means is not secured as for example the upward tilted end portion of the horizontal L-shank of the counterlocking means is arranged too low for a proper engagement with the hook-like locking means. Therefore, even if the master door is closed and the interconnecting rod is in engagement position the corresponding slave door could be opened by operating its door handle.